1. Field of the Invention
The present invention relates to an in-wheel motor drive device in which a load acting on a speed reducer, reduction gear or the like during a low temperature drive can be relieved.
2. Description of Related Art
In the in-wheel motor drive device of a type in which a lubricant oil supplied under pressure by an oil pump is supplied to a motor and various parts of a speed reducer, proper oil supply to sites where the heat release value is markedly high is effective to efficiently avoid an abnormality resulting from the heat release. Along therewith, the stirring resistance by a rotating member can be lowered as compared with the dip-feed lubrication and, therefore, it is specifically effective in terms of improvement in efficiency. In particular, an effect of lowering the stirring resistance of the oil is prominent under a low temperature condition in which the viscosity of the lubricant oil is high and a high speed rotating condition.